Plastic Extruder Components

The main machine of the plastic extruder is the extruder, which consists of an extrusion system, a transmission system and a heating and cooling system.
extrusion system
The extrusion system includes a screw, barrel, hopper, die, and die. The plastic is plasticized into a uniform melt through the extrusion system, and is continuously extruded out of the die by the screw under the pressure established in the process.
⑴Screw: It is the most important component of the extruder. It is directly related to the application range and productivity of the extruder. It is made of high-strength and corrosion-resistant alloy steel.
⑵ Barrel: It is a metal cylinder, generally made of alloy steel or composite steel pipe lined with alloy steel that is heat-resistant, has high compressive strength, is strong, wear-resistant, and corrosion-resistant. The barrel and screw cooperate to achieve the crushing, softening, melting, plasticizing, exhausting and compaction of plastic, and continuously and evenly transport the rubber material to the molding system. Generally, the length of the barrel is 15 to 30 times its diameter, in order to ensure that the plastic is fully heated and fully plasticized.
⑶ Hopper: The bottom of the hopper is equipped with a cut-off device to adjust and cut off the material flow. The side of the hopper is equipped with a sight hole and a calibration metering device.
⑷ Machine head and mold: The machine head is composed of an alloy steel inner sleeve and a carbon steel outer sleeve. The molding mold is installed inside the machine head. The function of the machine head is to convert the rotating plastic melt into parallel linear motion and introduce it into the mold evenly and smoothly. sleeve and give the plastic the necessary molding pressure. The plastic is plasticized and compacted in the barrel, and flows into the machine head forming mold through the porous filter plate along a certain flow channel through the machine head and neck. The mold core and mold sleeve are properly matched to form an annular gap with a continuously decreasing cross-section, so that the plastic melt can A continuous and dense tubular coating is formed around the core wire. In order to ensure that the plastic flow channel in the machine head is reasonable and eliminate dead corners where plastic accumulates, a diverter sleeve is often installed. In order to eliminate pressure fluctuations during plastic extrusion, a pressure equalizing ring is also installed. The machine head is also equipped with a mold correction and adjustment device to facilitate adjustment and correction of the concentricity of the mold core and mold sleeve.
According to the angle between the material flow direction of the extruder head and the center line of the screw, the extruder head is divided into an oblique angle head (included angle 120o) and a right-angle machine head. The shell of the machine head is fixed to the fuselage with bolts. The mold inside the machine head has a mold core seat and is fixed to the machine head inlet port with a nut. The front of the mold core seat is equipped with a mold core, a mold core and a mold core seat. There is a hole in the center for passing the core wire, and a pressure equalizing ring is installed on the front of the machine head for equalizing the pressure. The extrusion molding part consists of a mold sleeve seat and a mold sleeve. The position of the mold sleeve can be adjusted by bolts and supports. , to adjust the relative position of the mold sleeve to the mold core to facilitate adjusting the uniformity of the thickness of the extruded cladding layer. The outside of the machine head is equipped with a heating device and a temperature measuring device.